This invention is related generally to apparatus for removably attaching dental structures in an oral cavity, such as bridgework or a partial denture. Dental attachment structures are characterized as comprising a male element, a female element and a connecting element.
A removable dental attachment structure presents special problems because of the necessary requirements of balance between rigidity and flexibility insuring positive stabilization without damage to soft tissue and bone structure adjacent the area to be bridged. If the attachment structure is too rigid, damage can result during normal use. If the structure is too loose, it may be dislodged inadvertently causing inconvenience and embarrassment to the wearer. One solution to the attachment problem is described in U.S. Pat. No. 4,209,904 in the name of the present inventor which describes an improvement over the Dolder bar and clip for use with a partial denture.
Telescopic attachment structures designed for easy removal present a further class of problems. Telescopic attachment structures comprise a female element with a female guideway defined along an engagement axis, a male element with a male railway which is intended to telescopically engage the female guideway along the engagement axes. Various forms of securing the female element to the male element have been developed to promote a releasable interlock between the female element and the male element. Among the developments in telescopic attachment structures have been replaceable elastomeric or like sleeves for placement between the female element and the male element and elastomeric or like coatings on the surfaces of the female element and the male element. U.S. Pat. No. 4,362,509 issued to Josef M. Sulc describes some examples of sleeves which totally separate the functional portions of the female guideway from the mail railway. This patent appears limited to structures wherein the insert completely separates the female guideway from the male railway and otherwise shields the functional portion of the male element from the functional portion of the female element.
One form of a resilient fit is found in a form of extracoronal attachment sold by APM-Sterngold of San Mateo, California under the name "Hader Vertical Extension" in which the male element and the female element are normally in direct frictional contact. The present invention represents a departure from and an advance over these types of telescopic attachment structures.